Transfer ud

Add transfer_ud extrinsic to the pallet universal-dividend.

@librelois Je suis parti du code de balances.

• Est-ce un problème de multiplier le montant avec * quand les valeurs ne sont pas vérifiées ? (risque d'overflow ou de panic)

pallets/universal-dividend/src/lib.rs

@@ -27,11 +27,12 @@ mod tests;
 #[cfg(feature = "runtime-benchmarks")]
 mod benchmarking;
 
-use frame_support::traits::Currency;
+use frame_support::traits::{tokens::ExistenceRequirement, Currency};
 use sp_arithmetic::{
     per_things::Permill,
-    traits::{One, Zero},
+    traits::{One, Saturating, Zero},
 };
+use sp_runtime::traits::StaticLookup;
 use sp_std::prelude::*;
 
 const OFFCHAIN_PREFIX_UD_HISTORY: &[u8] = b"ud::history::";
@@ -251,5 +252,47 @@ pub mod pallet {
             n.encode_to(&mut key);
             sp_io::offchain_index::set(key.as_ref(), ud_amount.encode().as_ref());
         }
+        fn inner_transfer_ud(
+            origin: OriginFor<T>,
+            dest: <T::Lookup as StaticLookup>::Source,
+            value: BalanceOf<T>,
+            existence_requirement: ExistenceRequirement,
+        ) -> DispatchResultWithPostInfo {
+            let transactor = ensure_signed(origin)?;
+            let dest = T::Lookup::lookup(dest)?;
+            let ud_amount = <CurrentUdStorage<T>>::try_get()
+                .map_err(|_| DispatchError::Other("corrupted storage"))?;
+            T::Currency::transfer(
+                &transactor,
+                &dest,
+                value.saturating_mul(ud_amount),
+                existence_requirement,
+            )?;
+            Ok(().into())
+        }
+    }
+
+    // CALLS //
+    #[pallet::call]
+    impl<T: Config> Pallet<T> {
+        /// Transfer some liquid free balance to another account, in UD.
+        #[pallet::weight(0)]
+        pub fn transfer_ud(
+            origin: OriginFor<T>,
+            dest: <T::Lookup as StaticLookup>::Source,
+            #[pallet::compact] value: BalanceOf<T>,
+        ) -> DispatchResultWithPostInfo {
+            Self::inner_transfer_ud(origin, dest, value, ExistenceRequirement::AllowDeath)
+        }
+
+        /// Transfer some liquid free balance to another account, in UD.
+        #[pallet::weight(0)]
+        pub fn transfer_ud_keep_alive(
+            origin: OriginFor<T>,
+            dest: <T::Lookup as StaticLookup>::Source,
+            #[pallet::compact] value: BalanceOf<T>,
+        ) -> DispatchResultWithPostInfo {
+            Self::inner_transfer_ud(origin, dest, value, ExistenceRequirement::KeepAlive)
+        }
     }
 }